Early motor resonance differentiates schizophrenia patients from healthy subjects and predicts social cognition performance

• Published in: Progress in brain research Vol. 247; p. 353
• Main Authors: Mehta, Urvakhsh Meherwan, Ashok, Abhishekh Hulegar, Thirthalli, Jagadisha, Keshavan, Matcheri S
• Format: Journal Article
• Language: English
• Published: Netherlands 2019
• Subjects: Adult; Antipsychotic Agents - therapeutic use; Cognition - drug effects; Cognition - physiology; Evoked Potentials, Motor - drug effects; Evoked Potentials, Motor - physiology; Female; Healthy Volunteers - psychology; Humans; Male; Middle Aged; Schizophrenia - drug therapy; Social Behavior; Transcranial Magnetic Stimulation - methods; Psychosis; Time course; Mirror neuron activity; Temporal sequence; Social cognition
• ISSN: 1875-7855; 1875-7855
• DOI: 10.1016/bs.pbr.2019.03.011

Diminished motor resonance (facilitation of motor potentials during action observation) is possibly related to social cognition deficits in schizophrenia. Adequate social cognition requires the successful moment-to-moment appraisal of social stimuli over a temporal window. However, similar changes in motor resonance with successive action observation stimuli are unknown. We compared the time-course of motor resonance evoked during successive action observation stimuli between schizophrenia patients (antipsychotic-naïve and medicated) and healthy subjects and examined its association with social cognition performance. Fifty-four schizophrenia patients (33 antipsychotic-naive) and 45 healthy subjects underwent 10-recordings (T1 to T10) of cortical reactivity, using two single (sp)- and two paired-pulse (pp) transcranial magnetic stimulation (TMS) paradigms, while they observed goal-directed actions and a static image. They also underwent comprehensive social cognition assessments. Sp-motor resonance revealed a significant quadratic time effect (initial fall and then rise) in patients and healthy subjects [F=12.21, P=0.001]. Such a pattern was not observed for pp-motor resonance. We categorized motor resonance as early (T1-T3), middle (T4-T7) and late (T8-T10) based on pair-wise comparisons. Early, but not middle or late sp-motor resonance was reduced in antipsychotic naïve patients compared to the medicated patients and healthy subjects (F=3.41, P=0.037). Social cognition composite score had significant correlations with both early sp-motor resonance (r=0.34, P=0.01) and early pp-motor resonance (r=0.314, P=0.02) in the combined patient group. Motor resonance time-courses did not vary across groups. The magnitude of early motor resonance was reduced in the antipsychotic-naïve schizophrenia group, compared to healthy subjects. Early phase motor resonance was associated with social cognition deficits in patients.